From time to time, we run live experiments on Google — tests visible to a relatively few people -- to discover better ways to search. We do this because there’s no good substitute for understanding how real people, in real-world situations, actually operate. Theories are fine, but “improving the user experience” really happens best when we understand what people do online.

So to learn more, we sometimes randomly select a group of people to see a possible improvement to search options. Or we may select a group of people and try out a new element while they're searching. If you ever wonder why your Google site looks slightly different from that of the person sitting next to you, this is why.

We are currently testing new ways to refine searches so that, for example, a search for jobs might offer a choice of job location or function, rather than forcing you to continually narrow the terms you type in to a standard Google search.

We’ve run another test to learn more about how people navigate to find the information most relevant to them: how you might find image search or information in Froogle, for example, when that might be just the thing you want. Here’s how that one looks.

And we test ways to enrich web results, such as by offering a "Remove Result" option that would omit particular results from future searches if you decide they’re not useful. You'll see this feature if you're already signed in to a Google service when you perform your web search.

There's no set schedule when we'll roll out these sorts of new ideas (if at all), but these tests help us to improve your search experience.

p.s.: Google is also active in CHI, the major organization on user experience and usability. We're participating in the annual conference this week in Montreal. More here.